Browsing by Author "Rahatekar, Sameer S"

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    Assessment of the mechanical and microstructural performance of waste kraft fibre reinforced cement composite incorporating sustainable eco-friendly additives
    (MDPI, 2024-08-30) Taiwo, Anuoluwapo S; Ayre, David S; Khorami, Morteza; Rahatekar, Sameer S
    This study investigates the influence of limestone powder and metakaolin as sustainable eco-friendly additives on the properties and behavior of cementitious composite boards, with a focus on mechanical strength, physical properties, and microstructural characteristics. The experimental investigation begins with the characterization of the raw materials, including limestone powder, and metakaolin, to assess their particle sizes, elemental composition, and microstructural features. Cement composite boards were fabricated using an innovatively developed lab-simulated vacuum dewatering process, by varying the proportions of limestone powder and metakaolin as partial replacements for cement, along with waste kraft fibres as reinforcement. Mechanical testing was conducted to evaluate the flexural strength and behaviour of the composite boards according to standardized procedures. A microstructural analysis was performed using scanning electron microscopy (SEM) to examine the effect of additives on the cementitious matrix, fibrematrix interaction, and hydration products. The findings from the experimental study reveal insights into the influence of limestone powder and metakaolin on the mechanical properties and microstructure of waste kraft fibre-reinforced cement composite boards. Our analysis of the results shows that adding 9% limestone powder as partial cement replacement produces a 24% and 50% enhancement in flexural strength at 7 and 28 days of hydration, while that of metakaolin as partial cement replacement was optimum at 6% with an enhancement of 4% and 36%, respectively, at 7 and 28 days of hydration. The implications of these findings for the development of sustainable cementitious composite are discussed, including the potential benefits of using limestone powder and metakaolin as supplementary cementitious materials in waste kraft fibre-reinforced cement composite boards. Finally, recommendations for optimizing additive proportions are also provided to enhance the understanding and application of these materials in the construction and building industries.
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    Development and characterisation of integrated wet-spun alginate-Moringa oleifera composite fibers for potential water purification
    (Elsevier, 2025-03) Orisawayi, Abimbola Oluwatayo; Koziol, Krzysztof; Rahatekar, Sameer S
    Ensuring access to safe drinking water requires effective materials and technologies to treat contaminated water. In this study, we developed sodium alginate fibre (SAlgF) and their composite fibres functionalised with pulverised Moringa oleifera (MoP) at concentrations of 0.5 %, 1 %, 4 %, and 8 % using the wet-spinning technique. Both SAlgF and MoP are biodegradable, offering eco-friendly alternatives to synthetic polymers in line with green manufacturing. The results showed significant improvements in the mechanical properties, with the 1 % MoP composite fibre exhibiting 6 times the strength of pure SAlgF in terms of ultimate tensile strength (UTS) and Young's modulus (YM). X-ray Diffraction (XRD) analysis revealed enhanced fibres interactions, while Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA) confirmed the successful incorporation of MoP into the alginate matrix and improved thermal stability. Furthermore, the result obtained from the Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDX) indicated morphological changes and the uptake of heavy metal ions when immersed into solutions containing Cu²⁺, Ni²⁺, and Cd²⁺. These findings demonstrate the potential of MoP-modified composite fibres for sustainable and cost-effective water treatment applications, particularly in developing countries.
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    Modulating the properties of brown alga alginate-based fibers using natural cross-linkers for sustainable textile and fashion applications
    (American Chemical Society , 2024-09-03) Badruddin, Ishrat J; Silva, Mariana P; Tonon, Thierry; Gomez, Leonardo D; Rahatekar, Sameer S
    Seaweed-derived alginate shows promise in the textile industry as a sustainable alternative to synthetic and natural materials. However, challenges arise due to its low mechanical strength. We addressed this limitation by sustainably extracting alginates from European brown algae and employing novel manufacturing methods. Using natural cross-linkers, such as chitosan, ferulic acid, and citric acid, we have successfully modulated the mechanical properties of alginate fibers. Mechanical properties of ferulic acid and citric acid-cross-linked alginate solutions were spinnable, producing fibers with a diameter of 73–75 μm. Ferulic acid cross-linked alginate fibers exhibited stiffness, with a tensile strength of 52.97 MPa and a strain percentage of 20.77, mechanical properties comparable to those of wool, polyester, and rayon. In contrast, citric acid-cross-linked fibers showed partial elasticity, with a tensile strength of 14.35 MPa and a strain percentage of 45.53, comparable to those of nylon. This ability to control the mechanical properties of seaweed-derived fibers represents a significant advancement for their application in sustainable textiles and the fashion industry.